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US 2014/0212349 A1Published application
Process and device for the purification of waste gases
AssigneeChemisch Thermische Prozesstechnik GmbH
InventorChristian Mülleder
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AssigneeChemisch Thermische Prozesstechnik GmbH
InventorChristian Mülleder
Estimating the term…
For the purification of waste gas containing nitrogen oxides in combination with CO, VOCs or nitrous oxide, in particular waste gas resulting from the production of cement clinker, nitric acid, adipic acid, fertilizers and uranium trioxide, a regenerative thermal post-combustion system with at least two regenerators (A, B) is used by means of which the CO, VOCs and nitrous oxide are thermally purified in the combustion chamber (1) at a temperature of 800 to 1000° C. and the nitrogen oxides are thermally reduced with the SCR catalyst (6) by adding a nitrogen-hydrogen compound, wherein the waste gas already thermally purified is removed from the respective two-part regenerator (A or B) at a suitable place at a temperature of approx. 300° C., guided via the SCR catalyst (6) in a constant direction of flow and subsequently fed back to the remaining section (A′, B′) of the regenerator (A or B).
Process for the purification of waste gas containing thermally purifiable compounds oxidizable with the oxygen in the waste gas as well as nitrogen oxides and/or compounds forming nitrogen oxides during the thermal purification in a post-combustion system having at least two regenerators (A, B. . . ) filled with heat-accumulator bodies (3) and connected to a common combustion chamber (1), wherein the waste gas is alternately supplied to a raw gas inlet regenerator (A or B), the heat-accumulator bodies (3) of which have been preheated, and the thermally purified waste gas emerging from the combustion chamber (1) is supplied to a clean gas outlet regenerator (B or A) for the heating of its heat-accumulator bodies (3) and the selective catalytic reduction of the nitrogen oxides to nitrogen by means of a reducing agent, characterized in that at least two regenerators (A, B . . . ) are each divided into two parts in the direction of flow, namely into a section of the regenerator (A′, A″;
Process according to one of the preceding claims, characterized in that the the nitrogen oxides existing or being formed in the combustion chamber (1) can thermally be pre-denitrified by feeding a reducing agent into the combustion chamber (1).
Process according to one of the preceding claims, characterized in that the temperature in the combustion chamber (1) is at least 800° C. and, in case of thermal denitrification, at least 900° C.
Process according to one of the preceding claims, characterized in that, after having been mixed with the reducing agent, the thermally purified waste gas preferably flows through a ceramic packaging material (15) for homogenizing the temperature of the waste gas before it enters the catalyst (6).
Process according to one of the preceding claims, characterized in that a nitrogen-hydrogen compound is used for reducing the nitrogen oxides in the combustion chamber (1) and/or to nitrogen with the catalyst (6).
Process according to one of the preceding claims, characterized in that the residence time of the waste gas in the combustion chamber (1) is 0.3 to 1 seconds and, in case of thermal denitrification, 1 to 4 seconds.
Process according to one of the preceding claims, characterized in that a further regenerator (A to E) is provided for purging the raw gas inlet regenerator (A to E) with clean gas before the latter's passing to the clean gas outlet regenerator.
Device for carrying out the process according to one of the preceding claims, characterized by a post-combustion system with at least two regenerators (A, B) having a common combustion chamber (1) which each have two sections (A′, A″;
Dependencies are inferred from the claim text.